Funny Noise at Redline?

vesnyder · vesnyder's Garage

Last night was out driving the pi** out of my car when I noticed a strange sound just before reaching redline - it sounded a bit like a chain dragging? I could not consistently get it everytime? A little hard to hear over my screaming engine, but with a Cab with the top down I hear just about everything (usually music to my ears!).

I am probably overdue for a valve adjustment - is this a sign?

Rot 911 · 08-22-2003, 05:13 AM

Just to give this a bump back up to top. Normally the chain dragging sound is a collapsed chain tensioner, but this is normally heard at idle and lower rpm's.

billwagnon · 08-22-2003, 09:17 AM

patient: "it hurts when I do this"
doctor: "well, don't do that!"

not really an option about redline, though, is it?

nostatic · nostatic's Garage

Maybe rattling sheet metal (cat, muffler, etc)? I occasionally get that sound, although I don't think I have since the tensioners were updated. I'll have to redline a few times on the way home to let you know.

"honest officer, I was doing an experiment to help a friend out"

dotorg · 08-22-2003, 11:09 AM

Could it be pinging?

Doug Zielke · 08-22-2003, 11:55 AM

....Or the death rattle of broken headstuds?

Dan Owens · 08-22-2003, 12:12 PM

Or the slow disintegration of your engine

Bones · Bones's Garage

or the rev limiter?

North Coast Cab · North Coast Cab's Garage

Vance,
I told you not to post this. Keep that thing 500 from redline and you won't have the problem.

JG

North Coast Cab · North Coast Cab's Garage

Check this thread out, it may save you some money.

New RaceWare Studs / Bolts For Sale...

JG

needlevalve · needlevalve's Garage

I had a very similar occurance on my 75 911. Once I got to about 5500 I would get a weird chain type draging noise. It turned out to be carbon buildup on the pistons causing pinging via higher compression. I could make it go away by retarding the timing (more than I liked to for day to day driving), or by running 93 octane with additibes to the fuel. Would probably be worth the 10 buck to run a bottle of techron in the tank and see if there's any diff.

johncj8989 · 08-23-2003, 06:09 PM

Thats the sound you get just before you reach the point of terminal velocity and jump through a wormhole to an alternate universe.

Happens to me all the time at redline

Its a Porsche thing.

HawgRyder · HawgRyder's Garage

I have the idea in the back of my mind (shallow area I know LOL)...of putting a windsheild water bottle in the intake system.
For just this kind of problem...you would give the switch a quick shot when reving the engine to get rid of some of the carbon.
When putting a heavy load on the engine it heats the combustion chambers up as high as they will ever get....so...the water would break up the carbon deposits.
The danger here is that some of the carbon might stick on the valve seat...but at high RPM it would be harder for that to happen rather than at lower RPM.
Bob